Last week i sent an email to PMI but may be went to his spam box. I bought KSC3503ESTU;KSA1381ESTU from member sonnya a while ago for a low price. You can try if those are still available. Good luck, Loek
Other than the parts specifically noted as high power (the 5W 0.33 and the 2W 33 Ohm) all the other resistors will be ok at 1/4W. However, note Ivanlukic's comments - some of the reasons I prefer to use 0.5W.
I cannot see the detail in your board (layout etc) , but I would thicken up the power and high current tracks - look forward to seeing your final board!
0.46A of base current for 1W dissipation.
At 0.2Apk, the peak transient dissipation would be ~188mW.
Do the base stoppers need to be 1W?
They are easy to solder and can handle things nicely when you drive a 4 Ohm load. I've used them on the e-Amp . . . so I stick with it.
😉
😉
The problem is how to find sonnya's email address? I do not see members search tool.
I think i found it:
http://www.diyaudio.com/forums/members/sonnya.html
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indeed, look at his last posting in statistics and then you can rightclick his name and so on..
Thank you Bonsai for confirming that 1/4 watt resistors can be used and for recommendations on the board layout. I would have attempted this amp a while ago but for the lack of appropriate heatsinks. Now I am waiting, gathering a list of the corrections between schematic, BOM and the official PCB.
Make sure Samuel that you keep the feedback summing junction compact and close to the level shifting transistors (This is R11, R12-R16, R28, R29). Too much stray capacitance to GND could cause problems - this is a general requirement for CFA topology amplifiers.
Hi folks,
A while back Bonsai asked if I still had any BC546C and BC556C from an earlier group buy when the minimum quantity at Mouser was 10,000. I thought that they had been pitched in a move, but found about 1,000 of each recently on the back of a shelf. If someone wants to manage distribution, the lot can be had for the cost of shipping. Sorry, I can't ship small quantities. These are on a tape with pre-formed inline leads.
Bob
A while back Bonsai asked if I still had any BC546C and BC556C from an earlier group buy when the minimum quantity at Mouser was 10,000. I thought that they had been pitched in a move, but found about 1,000 of each recently on the back of a shelf. If someone wants to manage distribution, the lot can be had for the cost of shipping. Sorry, I can't ship small quantities. These are on a tape with pre-formed inline leads.
Bob
I can do that, I already have the mailing addresses for everyone who ordered boards so far, and I think we can ship these in a regular envelope (or try, at least). pm sent
PMI,
If there is another board run, please put me down for a stereo set, plus the PSU/protection board.
After Mark Brasfield joined the forum and got folks interested in the LME49713 CF op amp and then Richard Marsh's headphone amp, this really got my curiosity level up and wondered what such an amp to power speakers might look like. Kudos to Bonsai!
It will be cool to learn some things via this thread and the CFA thread. I just restored my Adcom GFA-535 and it's left me wanting to learn even more.
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PMI,
Are these KSC & KSA parts applicable to the VSSA build? Just wondering as some of these parts seem to be so coveted here and in other places?
Are these KSC & KSA parts applicable to the VSSA build? Just wondering as some of these parts seem to be so coveted here and in other places?
Yes. Same part.
This is partly why I have tried to stay out of the discussion and just read what other people have to say. In the other thread, no clear answer about what is desirable and why, emerged in my opinion. I can read the datasheets just fine, but knowing what makes a difference is another story.
Do you have a price, how shipped etc?
this was my last post on the subject:
Sonnya,
Thank you for the offer then on those devices. Are we going to make that part of a group buy for the VSSA project?
Thank you for the offer then on those devices. Are we going to make that part of a group buy for the VSSA project?